Odor-free liquid conjugated diene polymers



rates aired ODOR-FREE LEQEUKD CONJUGATED DIENE POLYMERS No Drawing. Application December 4, 1956 Saerial No. 626,079

15 Claims. (Cl. 106-285) This invention relates to odor-free, liquid conjugated diene polymer compositions. in a further aspect this invention relates to coating compositions, such as paints or varnishes, prepared from liquid polybutadiene or other liquid conjugated diene polymers, the resulting coating composition being substantially odor free.

Since the issuance of Patent Number 2,631,175 to W. W. Crouch, the use of liquid polymers of conjugated dienes produced as disclosed therein has steadily increased. A major appiication of such polymers is in the protective coating field. Varnishes based on these liquid polymers can be air-dried to yield finishes of high gloss and hardness or baked at elevated temperatures to produce tough, flexible films possessing excellent chemical resistance and thermal stability. Furthermore, these liquid polymers function effectively as modifying agents for improving the bodying and drying characteristics of conventional oils and alkyds.

One objection to the use of these polymers in coating compositions is their characteristic odor, sometimes de scribed as an aromatic odor or as the odor of naphthalene. This odor is readily apparent in the liquid composition and in a varnish prepared therefrom. When applied in a coating, the odor persists until the coating is dry.

The following are objects of our invention:

An object of our invention is to provide odor-free, liquid conjugated diene polymers. A further object of our invention is to provide varnish and paint compositions prepared from liquid conjugated diene'polymers, said coating compositions being substantially odor-free.

Other objects and advantages of our invention will be apparent to one skilled in the art upon reading the accompanying disclosure.

We have discovered that the odor of liquid conjugated diene polymers can be substantially eliminated by treating the liquid polymer with hydrazine or the methyl or ethyl derivatives of hydrazine. An advantage of this invention results in the fact that a very small amount of hydrazine or derivative thereof is necessary to provide an odor-free liquid diene composition. As little as 0.02 part by weight per l parts by weight of the liquid polymer is frequently satisfactory. Generally not over 0.2 part by weight is required although up to 2 parts by weight are sometimes used. Obviously, greater amounts can be used but this is not frequently done for two reasons. First, the smallest amount suitable is the most economic and, second, the use of a large excess will produce the characteristic hydrazine odor in the composition and this is not desired.

As stated, the polymers used in the production of the compositions of our inventions are preferably prepared according to the method of Crouch 2,631,175. This process is a mass polymerization one using finely divided sodium which produces a liquid polymeric material free from solid matter having an average molecular weight in the range of 500 to 5000. The product is substantially transparent and colorless. The polymers have a vis- 2,863,786 Patented Dec. Q, 1958 cosity of at least 100 Saybolt furol seconds at 100 F., this ranging up to approximately 6000 Saybolt furol seconds at 100 F.

While liquid polybutadiene is the material used in the examples of this application, the invention is applicable to polymers of other conjugated dienes such as isoprene, piperlyene, 2,3-dimethylbutadiene, and other conjugated dienes containing up to 8 carbon atoms per molecule. The invention is also applicable to copolymers of one or more of these dienes with vinyl compounds such as styrene, methyl substituted styrene, the vinyl pyridines, the acrylates, and the like. A particularly preferred copolymer is a copolymer of 1,3-butadiene and styrene. Where copolymers are used, the major polymerizable ingredient is the conjugated diene and this component is present in an amount which exceeds 50 percent by weight of the monomeric material.

Spirit varnishes are prepared by diluting the liquid conjugated diene polymer such as polybutadiene, with a solvent or thinner. Conventional thinners for paint and varnish are applicable i. e., coal tar hydrocarbons, petroleum distillates, turpentine fractions and the like. The amount of thinner is generally within the range of 20 to percent of the total composition on a weight basis, or, stated in other words, 25 to 400 parts by weight of thinner are used per 100 parts of the liquid polymer. Although films prepared from these liquid conjugated diene polymers will dry in the absence of promoters, the addition of conventional drier compositions will materially reduce the drying time and will improve the ultimate film hardness. The amount of drier is, of course, dependent upon the the properties desired in the final composition but this amount is generally within the range of 0.02 to 3 parts by weight per 100 parts of the liquid polymer. Driers which are commonly used are lead, cobalt, zinc, and manganese, in the form of the naphthenate or other salts. I

in preparing such a varnish the thinner is mixed with the liquid polymer and the driers are subsequently added. Oftentimes, it is desirable to warm the mixture to 200 to 250 F. to facilitate solution and to produce a homogeneous mixture.

As stated previously, the amount of hydrazine, methyl hydrazine, or ethyl hydrazine ranges from 0.02 to 2 parts by weight per 100 parts by weight of the liquid polymer although, in general, it is unnecessary to use more than 0.2 part by weight and 0.02 to 0.2 part constitutes a preferred range.

Another important use of these liquid polymers and one wherein the deodorizing subject of the present invention is important, is where the liquid conjugated diene polymer is used as a modifying agent for drying oils and alkyd resins. The drying and semi-drying oils used in clude linseed oil, tung oil, soybean oil, oiticica oil, castor oil, cottonseed oil, and perilla oil.

Varnish compositions of the present invention areapplied to work, metal, and surfaces of other types by any suitable means such as brushing,'spraying, dipping, roller coating, and the like. Following application of the varnish or paint, the material is generally baked at a temperature between 200 and 500 F, preferably .between 300 and 500 F. for a period in the range of 5 to minutes although the baking period seldom exceeds 60 minutes. I J

The hydrazine, methyl hydrazine, or ethyl hydrazine added to eliminate the odor of the liquid polymer can be added at any stage following the production and recovery of the liquid polymer. Generally it is added during the varnish or paint formulation although it is often added to the liquid polymer before storage or transportation,

The following examples are illustrative of our invention and the manner in which it may be practiced.

Example I A liquid hemopolymar ol" l,3-butadienc was prepared according to the mass pr orization process of Patent No. 2,63l,l75. This polymer, after removal of solvent therefrom hitd n. Density of 1500 Saybolt Furol scconds at l0 F. To 100 parts by weight of this liquid polymer added E00 parts by weight o! mineral spi and as dries. 0 0 part by weight of cob-'2 t .phthen; 0.8 part by n 1 of manganese naphthcnate, and 0.4 part by weight it lead naphthe .ntc. This mixture was stirred to pro a homogeneous solution. and divided into four per ens. llydraziue was added to three of these pnrlioi in amounts of. respectively. 0.i. 0.3. and

2 parts by weicht of hydrazine per 100 parts by wei t of the liquid no yl utadicne. the

No hydrazine was added to fourth portion which served as the Control. of wood were minted with each of the 'isltcs. Each painted piece of wood was to the fol owing series of tests in order to ti: the odor control by the use of hydrazine. each sample was placed in a seprnte c oud vessel for 2 hcurs. was allowed to dry in a' for :2 i d of time. and vns then returned to the l s tub; in order to permit the odor concentration to br 'l up. This procedure was repeated a series of times L all of the samples had completely dried.

Following each 24 hour p riod in the closed vessel, the intensity of odor of each piece was observed by three independent crvcrs. in each case. each observer was able to r the control sample as the one having the obnoxious odor.

Pieces of metal were likewise pointed with a portion of each of the (our varnish compositions and, again, the observers were able to picl; out the control at once.

in each case the difi'crcnce in odor became less notice able as the material dried but the characteristic odor of the polybutadiene is obnoxious and the odor present during the drying is a problem which it has been difficult to overcome.

Example I] To another portion of the same liquid polybutadiene, 3 percent by weight hydrazine was added and the mixture was stored at 140 F. for two weeks. At the end of this time the vessel was opened and it was apparent that the liquid polybumdiene had lost its characteristic odor. Of greater importance. is the fact that this odor did not return to the sample after two days of standing exposed to air.

As many possible embodiments can be made from our invention without departing from the scope thereof, it is to be understood that all matter set forth herein is to be interpreted illustrative and not unduly limiting the invention.

We claim:

1. A composition of matter comprising a liquid polymer of a conjugated diene containing 4 to 8 carbon atoms and a compound selected from the group con sisting of hydrazine and methyl and ethyl derivatives thereof. the amount of said hydrazine or derivative there of being sullicicnt to eliminate the odor of the liquid polymer but insufficient to produce an objectionable hydrazine odor.

2. The composition of claim 1 wherein said liquid polymer is selected from the group con isting of homopolymers of 1,3-butadiene and copolymers of l,3-butadiene and styrene.

3. A composition of matter comprising a liquid homopolymer of LS'butadiene suitable for use in a varnish composition and a compound selected from the group consisting of hydrazine and methyl and ethyl derivati es thereof, the amount of said hydrazine or derivative thereof being sufiicicnt to eliminate the odor of the liquid polymer but insufficient to produce an objectionable hydrazinc odor.

4. A composition of matter comprising a liquid homopolymer of 1,3-butadiene suitable for use in a varnish composition and hydrazine, the amount of said hydrazine being sufiicient to eliminate the odor of the liquid polyer, but insufficient to produce an objectionable hydrazine odor.

5. A composition of matter comprising a liquid polymer of a conjugated diene containing 4- to 8 carbon atz-ms and a compound selected from the group con 'ig of hydrazine and methyl and ethyl derivatives thereof, the amount of said hydrazine or derivative thereof being within the range of 0.02 to 2 parts by weight per 100 parts by weight of said polymer.

6. The composition of claim 5 wherein said liquid polymer is selected from the group consisting of homo polymers of LB-butadicne and copolymers of LE-hutm diene and styrene.

7. A composition of matter comprising a liquid polymer of a conjugated dieuc containing 4 to 0 carbon atoms and a compound selected from the group consiting of hydrazine and methyl and ethyl derivatives; thereof, the amount of said hydraz'ic or derivative thereof lficitlti within the range of 0.02 to 0.2 part by weight per I00 parts by weight of said polymer.

8. A composition of m ter comprising a liquid hor opolymer of l .3-butadiene suitable for use in a varnish composition and a compound selected from the group consisting of hydrazine and methyl and ethyl derivatives thereof. the amount of: said hydrazine or derivative there of being within the range of 0.02 to 2 parts by weight per l00 parts by weight of said polymer.

9. A composition of matter comprising a liquid homopolymer of 1,3-bntadicnc suitable for use in a varnish composition and a compound selected from the group consisting of hydrazine and methyl and ethyl derivatives thereof, the amount of aid hydrazine or d tlVC thereof being within the range of 0.02 to 0.2 part by weight per lOO parts by weight of said polymer.

10. A composition of matter ccmpriuing a liquid homo polymer of 1,3-butadinc suita lc for 1c in a varnish composition and hydrazine, the amount of said hydrazine being within the range of 0.02 to 2 parts by weight per I00 parts by weight of said polymer.

11. A composition of matter ccmpri" g a liquid homopolymer of ljbbu dine suitable for use in n varnish composition and hydrazine. the amount of said hydrazine being within the range of 0.02. to 0.2 part by weight per 100 parts by weight of said polymer.

12. A varnish composition comprising, on a weight basis:

13. A varnish composition comprising, on a weight basis:

arts Liquid polybutadiene u 100 Hydrazinc 0.1-2 Thinner 25400 Drier 002-3 1. A varnish composition compri ing approximately 100 parts by weight of liquid polybutadine and on a weight basis, the following ingredients:

5 15. A varnish composition comprising approximately References C d in th fil f his patent 100 parts by weight of liquid polybutadine and on 21 UNITED STATES PATENTS We ght basis, the following ingredients: 2,631,139 Mahan Mar. 10, 5

P3115 5 2,638,460 Crouch May 12, 1953 Mineral spirits 100 2,652,342 Gleason Sept. 15, 1953 C b l naphthgnate 3 2,669,526 Kocnecke Feb. 16, 1954 Manganese naphthenate 0 8 2,709,662 Koenecke y Lead naphthenate 0.4 FOREIGN PATENTS Hydrazine 0-2 10 703,935 Great Britain Feb. 10, 1954 

1. A COMPOSITION OF MATTER COMPRISING A LIQUID POLYMER OF A CONJUGATD DIENE CONTAINING 4 TO 8 CARBON ATOMS AND A COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDRAZINE AND METHYL AND ETHYL DERIVATIVES THEREOF, THE AMOUNT OF SAID HYDRAZINE OR DEIVATIVE THEREOF BEING SUFFICIENT TO ELIMINATE THE ODOR OF THE LIQUID POLYMER BUT SUFFICIENT TO PRODUCE AN OBJECTIONABLE HYDRAZINE ODOR. 